Damper for steam-boilers



J. R. ROBINSON. DAMPER FOR MULTITUBULAB. BOILBRS.

No. 32,533. Patented Jun@` 11', 1861.

UNITED-STATES.

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specification of Letters `Patent No. 32,533, @sesame-11,1861.

To cLZZ whom 'it may concern; i y p y Be it known that I, J. R. ROBINSON, of Boston, 1n the county of Suiolk and State of Massachusetts, have invented a new and useful Improvement in Dampers for Multitubular Steam-Boilers; and I do hereby de#` clare that the following is .a full, clear, and exact description of the same, reference being had `to l the` accompanying drawings, forming part of this specification, in`which` Figure l, is a side elevation, partly in section, of a horizontal multitubular boiler with my invention applied. r Fig.` 2, is a rear end view of the same.`

Similarl letters ofreference indicate corresponding parts inboth figures.

The object of this invention is so to control the draft through the upper and lower tubes of a horizontal multitubular boiler as` to counteract thenatural tendency ofthe gases ofcombustion to come out from the u per tubes at a higher temperature than from the lower ones.; -andto this end my invention consists principally in thecombination with a sliding damper applied in rear of the rear f tube sheet; of a stationary frameconstructed and applied as hereinafter specified."

To enable others skilled in the art to make and use my invention, I will proceed to describe its construction and operation.

A, is the shell oftheboiler; a, a, are the horizontal tubes; and B, the reartubesheet.` The smoke box in rear ofthe sheet B, into which the tubes c, a, ischarge, is not represented in the drawing. n l" @,is an upright frame bolted to, or other` wise secured in a stationary condition close in rear of the tubesheet B, for the reception of the flat sliding damper D. This frame has long horizontal openings Z), o?, each of which communicates directly with the rear mouths of one or moretiers of tubesas shown in Fig. 2, andthe said frame is furnished at its sides with upright guides c, c, to `guide the damperand keep `it close to the outer surface of the said frame.` `The thickness of the said frame, must be suliicienttokeep the damper at such distancefronrthe tube sheet B,`as to provide for the escape` of the gases from the upper tubes when the damper is lowered to cover the said tubes. j The bar like portions.

(Z, e, of the frame, which constitutethe partitions between the openings b', b2, may either t close to the tube sheet as illustrated by tZ, in Fig. l, or may have spaces between them and the sheet as illustrated by e, in the same figure, but I prefer to make one or more of the lower ones perfectly close like cZ, and one ormore of the upper ones partly open like c. i

The damper may be raised and lowered by any convenient means. I have represented it suspended by a rod g, from the arm Zt, of a rocksshaft z', which works in xedbearings Z, Z, on the top of the boiler, and the arm a rod 7c, with a lever. E, conveniently ary y', of the said rock-shaft being connected by ranged near the front of the boiler to be op-` erated by the engineer or fireman to adjust the damperatany height.` This arrangement requires the rod g, to work throughlthe smoke box. v

when the damper israised entirely above) y 1 the wholemof thetubes a, a, as shown .in Fig.

2the' gasesleave the upper tubes whi'chare near the surface of the water at a very high temperature, and leave the lower tubes at` p a gradually lower temperature toward the bottom of the boiler the lowest tubes being .l

very cool.` This action is the saine as in a boiler without a damper applied to the tubes,

and it is only necessary to raise the damper to this position when the tubes require to be cleaned out. When the damper is lowered over the mouths of the upper tubesas shown in Fig.` l, thedraft through those tubes, without being entirely obstructed, is so much checked by its having a downward direction given to it after leaving the tubes, as indicated by arrowsv inFig. l, that the draft through the `lower tubes is increased and the ga`ses""causedl to leaveythe severalftubes at a more nearly equal` temperature. The

bar like partitions LZ, c, in between the open ings 51,12', b2, lnthe frame C, serve toxe`n them `either entirely or partiallyl from the able the, damper to shut ofi" the tubes above 0 chimney. When the damper `is brought i down low `enough to cover a partition constructed like (Z, all the tubesabove are entirely closed, but when it is brought down to 3 one constructedlike e, there still remains a contracted opening between the tube sheet and the frame, for the exit of the gases, from the uppertubes,but the draft is `very-much checked. 9

` By theuse of the term"horizontal .mul-

titubular boiler I dopnot `mean to confine myself strictly to a precisely horizontal arrangement of the tubes, but have merely `used the term in contradistinctionto the termupright" ico les

What I claim Vmyinveutio 2in-oly desire to secure by Letters Patent; is, l. The combination withaslding damper, applied to lthe rear tube sheet of a hori- 5 zontal multitubular boiler, of a stationary frame C, interposedbetween the said damper aud the tube sheet to form a space between the tube sheet and damper, substantially as and for the purpose herein specified.

10 2. The construction of the so applied y 327,533 I .l

to the tube sheet or not, as shown at d, and 15 e, in Fig. 2, substantially as herein described.

. J. R. ROBINSON.

Witnesses:

LEWIS A'. TUCKER,

C. W. CowTAN. 

